1. Field of the Invention
This invention relates generally to algae culture methods. More particularly, it concerns improvements in the culturing of macroalgae in marine media so as to enhance productivity and decrease operating costs of such operations.
2. Description of the Prior Art
Algae are cultured for a variety of purposes, e.g., as a source of agar, to provide fodder for animal and fowl feeding, etc. In such culture operations, dissolved carbon n the forms of carbon dioxide and/or bicarbonate may be growth limiting for large scale cultivation of significant marine macroalgae. In addition, the culture seawater may not have the capacity to dissolve all the CO.sub.2 and bicarbonate the algae are capable of utilizing.
Current technology in macroalgae cultivation in ponds or raceways is performed under carbon limitation conditions, with attempts to overcome this typically by adding CO.sub.2 into seawater charged into the culture system or by bubbling it directly into the culture medium. Adjustment of pH is often used to increase the concentration of the dissolved CO.sub.2 and bicarbonate. However, such procedure still limits the amount of dissolved carbon available to consumption by the algae. In order to raise the carbon concentration capacity of seawater, the alkalinity must be raised, but direct addition of an alkaline reagent, e.g., NaOH, causes precipitation of important seawater ions, e.g., calcium or valuable nutrients such as nitrates and phosphates.
The present invention provides improvements in macroalgae cultivation though a technique for enhancing dissolved carbon concentrations in marine macroalgal culture systems.